US 3519811 A
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Description (OCR text may contain errors)
Jul 7, 1970 Filed April 19, 1967 3 Shocks-Sheet. 1
"l| mi iNVENTOR HENRY S. JACOBS ATTORNEY July 7, 1970 H. s. JACOBS 7 5 3 v FLOODLIGHT HOUSING AND SUPPORT Filed April 19, 1967 3 Sheets-Sheet 2 iilit l Z 14 INVENTOR HENRY S, JACOBS J y 97 H. s. JACOBS 3, 9,
FLOODLIGHT HOUSING AND SUPPORT Filed April 19. 1967 I 3 Sheets-Sheet 5 INVENTOR HENRY s. JACOBS ATTORNEY United States Patent Us. (:1. 24o-3 3 Claims ABSTRACT OF THE DISCLOSURE A floodlight housing includes an electrical socket that is secured either to a single threaded shaft which extends through an opening in the rear end of an elongated enclosure and is held against rotation, or to a pair of spaced screws which extend through two holes in the rear end of the enclosure. By tightening nuts on the single threaded shaftor on the pair of screws, the socket and lamp bulb therein are drawn inwardly and the flared sides of the lamp bulb are seated against a cushioning rubber gasket disposed about the inner periphery of the enclosure. A polished, thin-Wall reflector portion of the enclosure flares outwardly beyond the lens end of the lamp bulb. The housing is supported on a U-shaped leaf spring, formed of unbonded laminations, which is attached at the ends of its arms to diametrically opposed points on the enclosure. A flanged bracket is disposed within the U-shaped leaf spring, and the leaf spring and bracket are both secured to a base at their bottoms. A short biasing leaf spring is disposed between the bracket and the U-shaped leaf spring to normally hold the lower ends of the arms of the U-shaped leaf spring away from the bracket.
BACKGROUND OF THE INVENTION This invention relates to floodlights, and particularly to a floodlight housing and support adapted to protect the floodlight lamp bulb from the effects of vibrations and shock leads.
Floodlights find numerous applications where a high degree of illumination is required, and some of these applications subject the sealed beam, internal reflector type lamp bulbs commonly used in such floodlights to unusual strains due to shock loads and vibrations. For example, floodlights of the type considered herein are widely used on mobile construction equipment such as cranes, shovels, tractors, well rigs, etc., for operation of the equipment at night. The continuous vibration and large shock loads which are encountered in such applications will cause damage to the filament of the lamp bulb if provision is not made for dampening the eflects of both vibrations and shock loads.
Floodlights normally include a housing for the lamp bulb that mounts an electrical socket either of the threaded or bayonet type. It has been previously suggested that the electrical socket should be spring mounted in the enclosure of the housing in such a manner that it is urged rearwardly of the enclosure. The lamp bulb is thereby forced to seat itself against a seal disposed along the inner periphery of the enclosure adjacent its open forward end. The purpose of such a construction is to lock the lamp bulb within the enclosure of the housing and also to prevent the natural elements from damaging the electrical connections and structure within the enclosure. One disadvantage of such construction is that it is diflicult to insert a new lamp bulb into the socket because there is no resistance against which the installer can work. That is, since the electrical socket is urged rearwardly by springs, any attempts to insert the bulb will simply add to the effects of the springs and move the socket rearwardly. A further disadvantage is that the locking force holding the bulb in place is dependent solely on the spring force and cannot be varied.
To completely protect against the effects of vibration and shock, not only should the lamp be locked within the housing, but the support of the housing on the equipment should dampen the effects of vibration and shock. Previous attempts in this direction have required the use of complex, expensive constructions.
SUMMARY OF THE INVENTION According to the invention, there is provided a floodlight housing in which the floodlight lamp bulb can be locked in place within an elongated enclosure against a cushioning seal, thereby protecting the electrical connections and the internal structure of the housing from the eifects of the natural elements. This result is accomplished by providing means by which the electrical socket can be manually moved forward in the enclosure for the insertion of a lamp bulb and then drawn inwardly of the enclosure to a desired amount to have the flared sides of the lamp bulb seat against an annular sealing means. The socket and lamp bulb ferrule can be either a screw type or a bayonet type. The housing may also include an outwardly flared thin-walled reflector portion of the enclosure which has its inner surface polished and which extends beyond the lens end of the lamp bulb for protection of the lamp bulb, for dissipation of heat from the housing, and to increase illumination. Also, according to the invention, there is provided a support for a floodlight housing which will dampen shock loads and vibrations to protect the filament of the lamp bulb. The support includes a U-shaped leaf spring of simple and economical construction which is attached at its ends to diametrically opposed points on the housing and which is secured to a base at its bottom to provide a resilient support for the housing.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a wide view in elevation of one embodiment of floodlight housing and support in accordance with the invention. FIG. 2 is a front view of the floodlight housing and support of FIG. 1 with portions of the housing broken away and with portions of the support shown in cross section for clarity of illustration. FIG. 3 is a view in horizontal section taken in the plane of the line 33 of FIG. 2. FIG. 4 is a view in vertical section taken in the plane of the line 44 of FIG. 3. FIG. 5 is a view in horizontal section of a second embodiment of floodlight housing in accordance with the invention. Finally, FIG. 6 is a view in vertical section taken in the plane of the line 6-6 of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment, a sealed lbeam, internal reflector type lamp bulb 10 is mounted in a housing including a cast aluminum enclosure indicated generally by the reference numeral 11. The enclosure 11 is formed in a generally bullet shape which tapers from a minimum at its closed rear end to an annular step 12 formed on its inner periphery, and then outwardly therefrom in an outwardly flared, thin-wall reflector portion 13. An electrical socket 14 is disposed within the enclosure 11 towards the rear thereof. The socket 14 is secured to one end of a threaded shaft 15 which projects through an opening 16 in the rear end of the enclosure 11, and leads 17 for the socket 14 extend through a grommet 18 in an opening in the side of the enclosure 11. Laterally projecting means in the form of a hexagonal nut 19 is nonrotatably secured to the shaft 15 and is slidably received within an elongated passage 20 formed in an integral hub portion 21 extending inwardly from the rear end of the enclosure 11. The passage 20 is formed concentric with the opening 16 through the enclosure 11 and is of a hexagonal shape to mate with the nut 19 (see FIG. 4).
A wing nut 22 is threadedly received on the projecting end of the shaft 15. A short compression spring 23 is biased between a pair of washers 24 which respectively bear against the exterior of the rear end of the enclosure 11 and the wing nut 22.
An annular rubber gasket 25 is comented in place On the step 12. The lamp bulb 10, when secured in the electrical socket 14, is adapted to seat and seal against such rubber gasket 25.
To insert the lamp bulb within the housing, the wing nut 22 is loosened and the shaft 15 is forced through the opening 16 in the enclosure 11. This will move the socket 14 far enough toward the open end of the enclosure 11 so that the lamp bulb 10, when held in the hand, can be either screwed or twisted into the socket 14. The socket 14 will not rotate as the lamp bulb 10 is being inserted because of the engagement of the hexagonal nut 19 within the mating passage 20. When the lamp bulb 10 has been placed into electrical contact within the socket 14, the shaft 15 is released and the compression spring 23 urges the socket 14 and the lamp bulb 10 rearwardly to seat theoutwardly flaring sides of the lamp bulb 10 against the rubber gasket 25. The lamp bulb 10 is locked in place against the gasket by tightening the wing nut 22 in a desired amount. To remove the lamp bulb 10 from the housing it is only necessary to again loosen the wing nut 22 and move the shaft 15, socket 14 and lamp bulb 10 forward. The use of the compression spring 23 increases the sensitivity and range of locking of the lamp bulb within the housing. Although desirable, the compression spring 23 can be eliminated.
The gasket 25 is large and soft to cushion the lamp bulb 10 within the housing and to prevent the lamp bulb from Working out of the socket. Various types of rubber are usable, and it has been found practical to use a closed cell foam or sponge rubber which resists temperatures up to 175 Fahrenheit. The reflector portions 13 of the enclosure 11 will function to dissipate heat produced by the lamp bulb It This, coupled with the use of a high thermal conductive material such as aluminum for the enclosure 11, reduces the temperature in the line of contact between the lamp bulb 10 and the gasket 25 to a point where the use of rubber can be tolerated. For very high wattage lamps, or where a large number of lamps are closely spaced together or otherwise subejcted to unusually high ambient temperatures, silicone rubber may be used. The inner surface of the reflector portion 13 is polished to present an additional reflecting surface which substantially increases the distance of effective illumination. By extending the reflector portion 13 beyond the lens of the bulb 10, a further degree of protection is afforded to the bulb 10.
The support for the floodlight housing includes a base 26 having bolt holes 27 at each of its four corners to receive anchor bolts 28 to secure the base 26 to a working surface (see FIG. 1). The housing is attached to the base 26 by a U-shaped leaf spring 29 which, in the preferred embodiment, comprises three unbonded laminations of spring steel 30. The leaf spring 29 is disposed about a U-shaped bracket 31 having outwardly turned flanges 32 which define lateral limits for the leaf spring 29. The free ends of the spaced arms of the leaf spring 29 are connected to the enclosure 11 at diametrically opposed, parallel, flat seating surfaces 33 formed on enlargements of the cast enclosure 11. The connection of the U-shaped leaf spring 29 to the enclosure 11 is accomplished by mounting bolts 34 that extend through openings in the enclosure 11. A large washer 35 is disposed against the outer surface of the end of each arm of the leaf spring 29, and a nut 36 together with a pair of lock washers 37 releasably hold the large washer 35 and the U-shaped leaf spring 29 to the enclosure 11. An acorn nut 38 protects the exposed end of each of the mounting bolts 34. By loosening the nuts 36, the housing can be pivoted within the support to change the aim of lamp bulb 10.
The laminations 30 comprising the leaf spring 29 and the bracket 31 are secured to the base 26 by a support bolt 39 which passes upwardly through an opening in the base 26 and receives a spacer nut 40 and then passes through holes in the laminations 30 and in the bracket 31 and receives a locking nut 41. Suitable lock and spacing washers are provided on the support bolt 39.
A short biasing leaf spring 42 is disposed between the underside of the bracket 31 and the upper surface of the U-shaped leaf spring 29. This biasing leaf spring 42 is stiffer than the laminations 30 and forces the laminations 30 away from the bracket 31 adjacent the sides of the bracket. The U-shaped bracket 31 is dimensioned at its ends so that the U-shaped leaf spring 29 will press lightly on such ends.
The life of the lamp filament is a function of the filament support within the lamp and the shock to which it is subjected. The inertia of the housing is many times that of the lamp bulb 10 alone. By floating the entire lamp bulb and housing on the spring support described, it 18 possible to dampen shock loads and vibrations before they reach the lamp bulb and its heated filament. This eliminates the necessity of using special and expensive filament mountings.
The inertia of the housing tends to resist motion change. When the base 26 moves suddenly downward with respect to the housing, only a portion of this movement is transmitted to the housing. The difference is taken up by the progressive bending of the laminations 30 with a decrease in the clearance between the bracket 31 and the laminations 30. If cushioning in this direction is not needed, the biasing leaf spring 42 can be omitted.
When the base 26 moves suddenly upward, the housing tends to remain stationary, thereby causing the laminations 30 to be pushed downwardly and bulged outwardly. Lateral movement between the housing and the base is taken up by bending of the laminations 30 between the ends of the bracket 31 and the attachments of the laminations 30 to the housing.
If sudden fore and aft movement of the working surface is a problem, the flanges 32 of the bracket 31 can be omitted so that the laminations 30 are free to flex in the longitudinal direction of the housing. Even with the flanges 32, some fore and aft movement is permitted by clearance between the flanges 32 and the edges of the laminations 30.
An alternate embodiment of a floodlight housing is illustrated in FIGS. 5 and 6. The enclosure 43 is generally similar to the enclosure 11 of the first embodiment except that it has a flat rear end 44 provided on its inner surface with a pair of spaced, inwardly projecting lugs 45. A hole 46 extends through each lug 45 and the rear end 44. The electrical socket 47 has a pair of screws 48 received in openings normally provided therefor, and the screws 48 are restrained against rotation by having their heads cemented in place. The screws 48 project through the holes 46 and receive wing nuts 49 which bear against the outer surface of the rear end 44. The rubber gasket 50, which may be made hollow for increased resilience, is adapted to seat against the outwardly flaring sides of the lamp bulb.
To replace bulbs within the embodiment of FIGS. 5 and 6, it is necessary only to loosen the wing nuts 49 upon the screws 48 so that the socket 47 can be moved outwardly to release the lamp bulb from the rubber gasket 40. Whether the lamp bulb has a screw or bayonet type ferrule, the screws 48 will prevent rotation of the electrical socket 47 when the bulb is rotated. Once a neW bulb is inserted the wing nuts are tightened to draw the electrical socket 47 inwardly to seat the bulb against the rubber gasket 50. The lugs 45 provide a positive stop to the inward travel of the electrical socket 47.
Of course, this alternate embodiment of fioodlight housing can be mounted on the support previously described.
It will be seen from the foregoing description that the floodlight housing and support of this invention provides an excellent, though relatively simple and economical, means by which the sealed beam lamp bulb of the Hood light can be protected against shock loads and vibrations. By locking the lamp into the housing, the inertia of the housing aids the protection of the filament of the lamp and prevents vibrations from loosening the lamp in the electrical socket. The spring support for the lamp effectively dampens vibrations and shocks.
Even though the lamp bulb is effectively locked within the housing, it can be easily released and removed. New lamp bulbs can likewise be inserted with case.
While preferred embodiments of the invention have been described in detail to illustrate the invention, it will be apparent to persons skilled in the art that changes can be made in the embodiments shown without departing from the scope of the invention.
1. A fioodlight housing for a fioodlight lamp bulb which increases in diameter from its base toward its lens end, said housing comprising: an elongated enclosure open at its front end and having enclosing sides and a closed rear end provided with a hole and an elongated passage, said enclosure including an inner peripheral seat portion of a diameter less than the maximum diameter of said lamp bulb; annular cushion sealing means disposed on said seat portion; an electrical socket adapted to receive the base of said lamp bulb and disposed within said enclosure toward the rear end thereof; a threaded member mounting said socket and projecting through said hole in the rear end of said enclosure; a nut on the projecting portion of said threaded member, said nut being adapted to work against the exterior surface of said rear end of said enclosure whereby said nut may be loosened to move said threaded member and socket towards said open front end of said enclosure for insertion of said lamp bulb in said socket and whereby said nut may be tightened to draw said lamp bulb and socket into said enclosure and seat said lamp bulb against said cushion sealing means; and laterally projecting means non-rotatably affixed to said threaded member and adapted to mate with said passage to prevent rotation of said threaded member and socket throughout the length of travel of said threaded member.
2. A support for a fioodlight housing comprising: a base; and a generally U-shaped leaf spring rising from said base, said leaf spring being formed of a plurality of identical, unbonded laminations of spring material, said leaf spring having its spaced arms connected adjacent their ends to diametrically opposed points on said housing and said leaf spring being secured centrally at its bottom to said base.
3. A support for a floodlight housing comprising: a base; a generally U-shaped leaf spring rising from said base, said leaf spring having its spaced arms connected adjacent their ends to diametrically opposed points on said housing and said leaf spring being secured centrally at its bottom to said base; a generally U-shaped bracket disposed adjacent the inner surface of said leaf spring and having the ends of its spaced arms terminating short of the ends of the arms of said leaf spring, said bracket being also secured centrally of its bottom to said base; and a short, biasing leaf spring disposed between said bracket and said U-shaped leaf spring at the bottom thereof, said biasing leaf spring having its ends bearing against the arms of said U-shaped leaf spring to space such arms from said bracket.
References Cited UNITED STATES PATENTS 1,915,967 6/1933 Bailey 240-52 2,894,693 7/ 1959 Howarth 240- XR 2,933,273 4/ 1960 Koch 248-291 XR 2,024,858 12/ 1935 Highfill 240-90 XR 2,511,937 6/1950 Natale 240-90 XR 2,668,901 2/ 1954 Austin 240-3 2,699,491 1/ 1955 Sternaman 240-3 3,018,364 1/1962 Wenman 240-90 FOREIGN PATENTS 1,229,552 l/1960 France.
370,568 3/ 1923 Germany.
NORTON ANSHER, Primary Examiner R. P. GREINER, Assistant Examiner US. Cl. X.IR.